2.5L 2001 Forester.

Planning to change the belt myself at about 100K. Should I replace the toothed roller, smooth tensioner roller and the tensioner it self too? My old Mazda has that same kind of odd-ball tensioner and didn't seem to like to be reused. Any reasonable parts sources for these things. I priced out the above mentioned parts and it was $3~400.

 

Thanks for any advice.

Although it may be pricey, do it all, including seals and water pump. Seals are known to leak, and trust me, you only want to take it apart once.

Agreed. Assuming that's 100k miles. All the belt followers and the tensioner.

 

You should also replace the crank and cam seals. Water pump is a very good investment.